ORA-00918: 未明确定义列解决方法

  public IList<BizMain> GetALLBizMainByClientWorkCode(string w_workcode, string name)        {            string sql = "SELECT * FROM BizMain inner join BizProxy  on BizMain.WorkCode = BizProxy.WorkCode Where 1= 1";            sql += " And Client = '" + name + "'";            if (w_workcode != "")            {                sql += " And WorkCode like '" + w_workcode + "%'";            }            sql += "order by WorkCode asc"; List<BizMain> list = new List<BizMain>();            OracleDataReader dr = help.GetReader(sql);            while (dr.Read())            {                BizMain main = new BizMain();                if (dr["WorkCode"] != DBNull.Value) main.Workcode = Convert.ToString(dr["WorkCode"]);                if (dr["BLCode"] != DBNull.Value) main.Blcode = Convert.ToString(dr["BLCode"]);                if (dr["CKCode"] != DBNull.Value) main.Ckcode = Convert.ToString(dr["CKCode"]);                if (dr["Vessel"] != DBNull.Value) main.Vessel = Convert.ToString(dr["Vessel"]);                if (dr["Voyage"] != DBNull.Value) main.Voyage = Convert.ToString(dr["Voyage"]);                if (dr["PkgNumber1"] != DBNull.Value) main.Pkgnumber1 = Convert.ToInt32(dr["PkgNumber1"]);                if (dr["Weight1"] != DBNull.Value) main.Weight1 = Convert.ToInt32(dr["Weight1"]);                if (dr["Cubage1"] != DBNull.Value) main.Cubage1 = Convert.ToInt32(dr["Cubage1"]);                if (dr["CargoName"] != DBNull.Value) main.Cargocname = Convert.ToString(dr["CargoName"]);                if (dr["Destination"] != DBNull.Value) main.Destination = Convert.ToString(dr["Destination"]);                if (dr["Package1"] != DBNull.Value) main.Package1 = Convert.ToString(dr["Package1"]);                list.Add(main);            }            dr.Close();            return list;        }